What’s the Connection Between Sapphires and  Rubies?

What’s the Connection Between Sapphires and Rubies?

  • December 27, 2019
  • In Rubies
  • By Amy Huang

No one can doubt that the engagement rings worn by Kate Middleton and Princess Eugenie are absolutely gorgeous. But there are some who want to rain on their parade and say that, although gorgeous, the rings are just too similar. Did Princess Eugenie copy Kate Middleton’s ring? How closely do the rings take after each other, and why the uproar?

The interesting thing is that the ring worn by Princess Eugenie is not even based on Kate’s ring. It’s based on the ring worn by her mother, Sara Ferguson, Duchess of York. Likewise, Kate’s ring is not based on Princess Diana’s ring. It is Diana’s ring. Her sons kept it safe after her death and swore whoever got engaged first would have the ring for their fiancé.

The rings do look similar, but can we stop with this copy-cat calling and start admitting that the royal family has a tradition with their engagement rings? Kate’s is a sapphire with a diamond surround and Eugenie’s is a peach-red sapphire with a diamond surround. While the differences in the rings seem to be in the stones inset into each ring, that is one of their core areas of similarity.

The term “sapphire” on its own only refers to blue instances of the mineral corundum while red instances of corundum are called ruby. Upon first glance they look like totally separate gemstones, but they are scientifically the same material.

The Corundum Connection

You might be wondering why these gemstones are so sought after. First of all, corundum is a tough stable mineral. After diamond, it’s the second hardest mineral and that makes it a great abrasive. This is important because when hardness is found in gemstones you have the perfect recipe for cutting. Also, gem-quality corundum is rare. So, when you have the combination of hardness, popularity and rarity along with a storied history you have a sought-after gem.

In fact, these gemstones are so sought after that $464 million in sapphires and $149 million in rubies were imported into the USA during 2006, more than all others, except emeralds.

Are Rubies and Sapphires the Same?

But if the gems are both corundum, why are they different colors? The answer lies in trace elements that give these gems their colors. When titanium and iron come into corundum, you have a sapphire, blue. When chromium enters a corundum, it turns the gemstone red, and the name changes to a ruby.

But sapphires come in other colors too! When they are a color other than blue or red, they are called fancy sapphires. And they are very sought after as well.

The Sapphire Story

You might be wondering just how sapphires are made. Corundum forms in igneous rocks such as syenite or basalt and even in metamorphic rock such as schist or basal. Once there, impurities set in, which may or may result in a gem quality stones. If not, some treatments are available to make them gem quality.

Once mined, the sapphire might not have the clarity or color desired. Because of this, sapphires commonly go through treatments such as heat, that improve the clarity and color.

It should be stated that an unheated sapphire will be more expensive than a heated one.

So, what are the heat treatments? Sometimes sapphires are heated for brief periods of time at 400 degrees Celsius. This is predominantly done to pink sapphires from the mines of Madagascar. The process improves clarity, color and color zoning.

In higher heat, around 1700 degrees Celsius silk dissolves. Improving color and clarity, this extreme heating will be noticeable to a trained gemologist.

At a more average heat of 1200 to 1600 degrees star sapphires can be made or improved.

Sometimes chemicals are added along with heat to improve color and clarity, such as in the case of fracture filling. Sometimes fractures reach the surface compromising clarity. Without treatment this would be a low value stone. But if a chemical flux is added to these fractures, they end up either turning glassy or even healing the fracture. The result is a gem that has increased in value, due to its brighter color and better clarity. The downside of treating gemstones in this way is that it makes them fragile and they may chip. Also, sometimes heating does not work. As a last result we turn to diffusion.

When heating alone does not work, sometimes lattice diffusion is used. In lattice diffusion, very high heat almost to the stone’s melting point is used with beryllium to enhance the color of the stone.

Beryllium is used because of the small size of its atoms, meaning it can penetrate far into the gemstone and making detection of its use hard. It can make a huge difference in the color and clarity of the stone, and ethical stores will disclose its use.

Rubies Are Just Red Sapphires

Speaking of color and clarity, the ruby stands apart. Used extensively in jewelry as well as other forms of art, this gemstone has retained its popularity across the world.

It’s no wonder these gems are so sought after; transparent rubies of a large size are even rarer than diamonds!

Due to their popularity throughout the world, in the movies, (Dorothy’s red ruby slippers), and in real life, rubies have always stood apart as a gemstone, even though this gemstone is identical in every way but color to a sapphire. These stones are never called sapphires. They are always referred to as rubies.

Not all rubies are equal, however. In nature they come in colors that range from bright red to reddish brown. But the most sought-after rubies are a deep blood red with a bluish hue. Rubies must have a high level of transparency to be gem quality.

Synthetic Or Natural Rubies and Sapphires?

As I am sure you are now aware, natural sapphires and rubies come from the ground. They may get treated with heat or have some other treatment, but their origin, is in the Earth.

Synthetic gemstones are made in the lab. They have the same makeup, visual characteristics and hardness as those found in the ground.

To make a synthetic ruby there are two common methods: flame fusion and flux fusion. The goal of flame fusion and flux fusion is to melt the raw gem and then have it recrystallize. The flame fusion technique can make a gem quality ruby in a few hours and the flux method takes months.

It is hard to tell if a ruby is synthetic or natural. Only a trained gemologist can see the difference using a high-powered microscope.

Synthetic sapphires are made in the lab, replicating the heat and pressure needed to make a sapphire in nature.

Once again, only a trained gemologist will be able to tell the difference.

Why would someone want a synthetic ruby or sapphire as opposed to a natural one? Well, natural rubies and sapphires cost much more than synthetic ones. The synthetic ones are of high quality and have the same chemical, visual and physical features as natural ones. Despite this, the customer must always be told whether the sapphire is natural or synthetic.

In fact, “In the United States, the Federal Trade Commission requires that any gem material produced in a laboratory be described in a way that leaves no doubt that it was not produced naturally. It is considered to be a deceptive practice if a synthetic gem material’s origin is not clearly disclosed throughout the distribution channel at the time of sale, from the manufacturer to the consumer.”

Despite this, if you know what you are getting, there is nothing wrong with going with a synthetic sapphire. They have excellent clarity at an affordable price.

So, you are ready to look for a quality ruby or sapphire. How do you choose one? Remember the 4 C’s that apply to diamonds? Well guess what? They apply to sapphires and rubies too. They are Color, Clarity, Cut and Carat.

The color is the most important factor in the value. What you are going for, for rubies, is Pigeon Blood Red. No, I did not make that up. It has been said that a ruby should be the same color as the first two drops of blood from a freshly killed pigeon. It means a very vibrant red. Sapphires need to be not too dark, but otherwise a strong clear blue.

As far as clarity goes, the more visible the inclusions the less value the ruby has. If you go outside, the color should not change. Remember to ask if it has been heat treated or is synthetic.

As for cut, a ruby’s crystal shape determines how suitable it is for certain cuts. The most common cut is flat tabular hexagonal shape.

As for carat, large sapphires and rubies cost more than smaller ones, generally.

If sapphires and rubies intrigue you, make sure you come in for a free consultation. Our phone number and address are:

(619) 223-2151

DIAMONDS FOREVER
3689 Midway Dr. Suite A
San Diego, CA 92110

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